To put that into some context, Buruli ulcer reports totalled 107 for all of 2015. They have jumped in each year since then.

The Mornington Peninsula continues to be affected by the spread of the mysterious Buruli Ulcer, with infected patients continuing to be reported with greater numbers than the year before. Picture: Paul Jeffers

The rise in cases has led researchers to the brink of a new trial they hope will bridge a knowledge gap and answer questions about how the disease is transmitted to humans.

The Beating Buruli Project, headed up by Prof Stinear, is in the design phase of a mosquito control study. The "cluster randomised control trial" will target residential neighbourhoods with synthetic pyrethroid pesticide - a spray researchers say is perfectly safe.

They pesticide will likely be sprayed on nature strips between popular holiday suburbs Portsea and Rosebud.

Not everybody is happy about it. A change.org petition headlined "Mornington Peninsula insect massacre" has been signed more than 9000 times.

But Prof Stinear says the "world first" could finally help researchers prove mosquitoes are a carrier - something they have long hypothesised.

"For the majority of people it starts with a pimple on the limb. Most commonly it's on the legs or arms and it ulcerates in the middle. Typically, it's painless but some people can get a lump under the skin and the frightening version is very aggressive.

"In about 10 per cent of cases there's redness and swelling and pain, typically over a joint, that rapidly progresses."

Dr O'Brien said "nobody knows" why the Buruli ulcer is occurring in coastal Victoria when it is typically a tropical disease.

"What's it doing down there? We don't know. Therefore we don't know how to stop it going to other areas," he said.